, me ##so ##3 ##h ) . these promoters are not compatible with sensitive functional groups , limiting the substrate scope . despite the me ##chan ##istic possibility for cat ##aly ##sis , multiple equivalent ##s of the promoter are often required in order to effect the reaction . this limits the atom economy of the reaction . the elimination step is not reg ##ios ##ele ##ctive ; if multiple β @ - @ hydrogen ##s are available for elimination , various products are often observed as mixture ##s . this is highly und ##es ##ira ##ble from an efficiency stand ##point as ar ##du ##ous separation is typically required . elimination destroys a potential stereo ##cent ##er , decreasing the potential useful ##ness of the reaction .
, meso3h ). these promoters are not compatible with sensitive functional groups, limiting the substrate scope. despite the mechanistic possibility for catalysis, multiple equivalents of the promoter are often required in order to effect the reaction. this limits the atom economy of the reaction. the elimination step is not regioselective ; if multiple β @ - @ hydrogens are available for elimination, various products are often observed as mixtures. this is highly undesirable from an efficiency standpoint as arduous separation is typically required. elimination destroys a potential stereocenter, decreasing the potential usefulness of the reaction.